| 摘要 |
PURPOSE:To improve the accuracy of an inner and an outer cylindrical parts of a pulley made of synthetic resin, and to improve the strength of the whole of a pulley. CONSTITUTION:A synthetic resin part main body 2 formed around a rolling bearing 1 is formed of an inner diameter cylindrical part 3, an outer diameter cylindrical part 4, a disc part 5, and ribs 6 radially provided in the disc part 5. The rib 6 is divided into an inner rib 6a formed at a corner of the inner diameter cylindrical part 3 and the disc part 5 and an outer rib 6b formed at a corner of the outer diameter cylindrical part 4 and the disc part 5. In the disc part 5, a gate 7 is provided between the inner rib 6a and the outer rib 6b, and the melted resin pressure-filled from the gate 7 is smoothly flowed in a cavity to improve the accuracy of both the inner and outer cylindrical parts and the strength of each part. |
